Free and peptide amino acid net flux across the rumen and the mesenteric- and portal-drained viscera of sheep

This experiment was conducted to determine the significance of the peptide amino acid (PAA) contribution to amino acid (AA) net flux in the portal vein and to evaluate the capacity for peptide absorption in the different segments of the gastrointestinal tract of ruminants. Four sheep (64+/-3 kg BW) were fitted with catheters and blood flow probes, allowing AA net flux measurements across the portal- (PDV) and mesenteric (MDV)-drained viscera and the rumen. Sheep were fed at maintenance a diet containing hay and extruded peas (70:30). Peptide absorption was investigated by a dose infusion of a mixture of peptides (casein hydrolysate, Pro-Phe, beta-Ala-His, Gly-Gly) into the rumen. Control and postinjection net fluxes of plasma free amino acids (FAA) and PAA were determined. The concentration of plasma PAA was determined by quantification of amino acids before and after acid hydrolysis of samples first submitted to chemical deproteinization and ultrafiltration (3-kDa cut-off filter). During the control period a significant net release (12 mmol/h) of PAA was observed across the PDV, which accounted for 35% of the sum of FAA and PAA net fluxes. This PDV flux of PAA mainly resulted from a MDV release of PAA (15 mmol/h). The net flux of total PAA across the ruminal wall was not significantly different from zero, but uptake of peptide Ile and release of peptide Gly were observed. The injection into the rumen of the peptide mixture increased the net release of peptide essential AA (EAA) across the MDV (P < .05) and the PDV (P < .10), and of peptide Pro and Phe across the non-MDV (P < .10). Peptide Ile uptake by the rumen tissues was decreased by the injection (P < .05). Significant increases in peptide Pro and Gly arterial concentrations were observed (P < .05). The 3-Ala-His and Gly-Gly arterial concentrations and net fluxes across the PDV were not affected by their injections into the rumen. This study showed that PAA may contribute significantly to AA flux across the PDV of sheep, and that part of this flux can probably be attributed to peptide absorption from the gut lumen. When high concentrations of peptides are generated in the rumen the possibility of peptide absorption before the jejunum has to be considered.     

Electrolyte levels and net fluid and electrolyte movements in the gastrointestinal tract of weanling swine.

Electrolyte concentrations, osmolality and pH were determined in conventionally raised weanling swine fed a liquid diet. Incorporation of a dilution marker into the diet in combination with frequent feeding enabled estimations as to the sites of relative fluid and electrolyte absorption and secretion along the gastrointestinal tract. Unlike many other species the weanling pig depends largely on its large intestine for absorption of fluid and electrolytes with small changes in net fluid movement occurring along the jejunal and ileal segments. Additional observations included the absorption of water by the porcine stomach which increased dilution marker concentration by approximately twofold and the high osmolality values recorded in the small and large intestine. The implications of these observations are discussed with regard to pathogenesis of colibacillary diarrhea in the weanling pig.     

中药驱治羊胃肠道线虫效果试验

应用研究筛选出的中药方剂和剂量进行羊胃肠道线虫驱虫,经和伊维菌素对比试验,其驱虫效果差异不显著,但费用降低50%,显著提高了养羊的经济效益,便于生产中推广应用。     

Effect of the methodology on peptide amino acid concentrations in blood and plasma of sheep.

Different methodologies for the measurement of peptide amino acid (PAA) in blood and plasma were compared in sheep. Preparation of blood and plasma samples consisted of a deproteinization, either chemical with sulfosalicylic acid (0.04 g for 1 ml of sample) or physical by ultrafiltration (10,000-MW cut-off filters), with or without a subsequent ultrafiltration through a 3,000-MW cut-off filter. Peptide concentrations were determined by quantification of amino acid concentrations before and after acid hydrolysis of samples. Free amino acid concentrations were similar by all the method used (about 2.5 and 2.7 mM, for blood and plasma respectively). Peptide concentrations were higher with chemical deproteinization (10.6 and 4.2 mM, for blood and plasma respectively) than with physical deproteinization (5.7 and 3.3 mM, for blood and plasma respectively). When the deproteinized samples were further treated to remove material of molecular weight above than 3 kDa, peptide concentrations were significantly reduced, which indicates inefficiencies in the ability of the deproteinizing procedures in removing all the proteinaceous materials. Concentration of small PAA (< 3 kDa) in blood was about 1.5-fold that in plasma, mainly due to peptide Gly and Glu derived from the hydrolysis of the erythrocyte glutathione. The choice of a methodology for quantifying circulating peptides is discussed.     

胃肠道营养对动物机体免疫的影响

本文综述了胃肠道的营养途径和几种营养素对胃肠道局部及机体全身免疫系统的影响及存在的问题。     

Comparison of mucosal drug conjugative rates along the gastrointestinal tract of female sheep

The comparative distribution of p-nitrophenol UDP-glucuronosyl-transferase, 1-chloro-2,4-dinitrobenzene glutathione-S-transferase and sulphamethazine N-acetyltransferase activities was studied along the gastrointestinal mucosa of female Lacaune sheep. Gastrointestinal mucosa was characterized by a very low and unequal N-acetyltransferase activity when activities were expressed per g of wet organ. The duodenum contained highest activities (4.1 nmol/g min). When results were expressed per mg of cytosolic protein, the duodenal activity (0.64 nmol/mg min) was sixfold higher than in liver (0.11 nmol/mg min). There was a lack in N-acetyltransferase activity accepting isoniazid as substrate. Glucuronosyltransferase activity was approximately threefold higher in microsomal fractions of the mucosal lining of gastric and colonic intestine (0.43-0.58 nmol/g min) than in small intestine or caecum (0.10-0.26 nmol/mg min). Concerning cytosolic glutathione S-transferase activity, two- to threefold higher activities were obtained in omasum, jejunum, duodenum and ileum (1021-2164 nmol/g min) than in other parts (341-799 nmol/g min) when results were expressed per g of wet organ. These data were compared with corresponding hepatic activities determined in the same six female sheep.     

富骊酸对动物胃肠道微生物的影响研究

动物胃肠道正常微生物菌群是微生物与宿主在长期进化过程中逐步形成的,它可通过粘附素与黏膜上皮细胞受体粘附,然后占位定植形成生物屏障,以阻止外来致病菌在肠道的定植(Hentges等,1970)。     

Effect of intracerebroventricular injection of IGF-I on circulating growth hormone concentrations in the sheep

The effect of intracerebroventricular administration of IGF-1 on circulating growth hormone (GH) concentrations has been studied in sheep. Twenty sheep were fitted with jugular vein catheters and with indwelling cerebroventricular cannulae. IGF-I was injected into a lateral cerebral ventricle and changes in the circulating concentrations of GH were measured in jugular vein blood samples. Administration of saline had no effect on circulating GH concentrations over a 3-hr period, and administration of IGF-I (at 1, 3 and 10 micrograms/sheep) also had no significant effect on circulating GH concentrations. From these data we surmise that centrally administered IGF-I does not influence GH secretion and it seems probable that cerebrospinal fluid concentrations of IGF-I do not have a role in regulating GH release in sheep.     

Effect of seaweed on gastrointestinal microbiota isolated from Norwegian White sheep

The effects of a commercial seaweed (SW) product and extracts collected from wild SWs in the Northern Norway on cultivable commensal intestinal bacterial groups isolated from Norwegian White sheep ewes were studied in vivo and in vitro. Bacterial counts from faeces from the ewes fed with supplement which contained SW meal throughout the entire indoor winter period had significantly lower lactic acid bacteria (LAB) counts (P?≈?.05). The screening of extracts from red and brown SWs showed that a number of the organic extracts had an inhibitory effect on the growth of the two Enterococcus sp. isolates. The results indicate that Ascophyllum nodosum supplementation reduces LAB counts in the ewes and the lambs, and that extracts from this SW have an inhibitory effect on the growth of Enterococcus sp. isolates.     

伊维菌素注射乳液治疗绵羊胃肠道线虫病及螨虫病的试验

伊维菌素（IVM）注射液是一种广谱、高效、长效、环保的治疗性兽药,它可有效驱杀家畜线虫、螨虫及其他寄生性昆虫病。但长久以来,由于伊维菌素注射液辅料成本高,无形之中提高了企业的生产成本,加重了广大牧民的使用负担。鉴于此,沈阳市兽药厂自行研制了伊维菌素注射乳液。其与伊维菌素注射液比较,所用辅料成本低廉并有缓释效果,为验证其疗效特做此实验。     

Ultrasonography of the urinary tract of female sheep.

We determined the position, dimensions, and structure of the kidneys, ureters, bladder, and urethra of 62 female sheep by use of ultrasonography. A 5.0-MHz convex transducer was placed over the right flank to examine the kidneys, and a 5.0 MHz-linear transducer was used to examine the bladder and urethra transrectally. All examinations were performed on sheep in standing position. The left kidney was 7.1 to 8.9 cm long, 3.4 to 5.5 cm wide, and 3.3 to 4.7 cm deep. Diameter of the parenchyma and renal sinus of the left kidney ranged between 1.1 and 1.9 cm and 1.1 and 2.0 cm, respectively. Circumference of the medullary pyramids varied between 2.1 and 3.3 cm. Similar ultrasonographic measurements were obtained for the right kidney. The diameter of the bladder varied between 0.3 and 6.9 cm in 96.8% of the sheep. The diameter of the bladder could not be determined in 32% of the sheep because it was > 10 cm, and, therefore, was beyond the penetration depth of the scanner. The only part of the urethra that could be ultrasonographically visualized was the internal urethral orifice. It had diameter between 0.1 and 0.2 cm. The ureters could not be ultrasonographically visualized in any of the sheep examined. The urinary tract of 8 sheep was examined 10 times within 2 weeks to examine whether measurements were reproducible. The interassay variation coefficient determined ranged from 3.1 to 31.8%, although for most variables, it ranged between 5 and 11%.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of dietary pH and phosphorus source on performance, gastrointestinal tract digesta, and bone measurements of weanling pigs.

Crossbred pigs (n = 144, average age and weight = 28 +/- 3 d, 7.5 kg) were used in two 6-wk trials to assess the effects of dietary pH and P source on growth performance, gastrointestinal digesta pH and chloride ion concentration (Cl-), and bone characteristics. Treatments were randomly allotted within blocks (based on weight within gender) to a 3 x 2 factorial arrangement with three dietary pH levels (5.4, 6.0, and 6.7) and two P sources: dicalcium phosphate (DCP) and defluorinated phosphate (DFP). Pigs fed the pH 6.7 diet had reduced ADG (P less than .01) and average daily feed intakes (ADFI; P less than .001) during wk 1 to 3 and overall compared with pigs fed the pH 6.0 diet, but ADG and ADFI were not affected when the pH 5.4 diet was fed. There was a dietary pH x P source interaction (P less than .05) for ADFI. Pigs had decreased ADFI as dietary pH was increased from 6.0 to 6.7 for both DCP and DFP, but ADFI was similar for the pH 6.0 and 5.4 diets with DFP, whereas ADFI was greater for the pH 5.4 diet with DCP. Dietary pH did not influence ADFI:ADG ratio (F:G; P greater than .05), and P source had no effect (P greater than .05) on either ADG, ADFI, or F:G.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of probiotics on enrofloxacin disposition in gastrointestinal tract of poultry

Probiotics are routinely used in poultry husbandry due to health benefit on the host. The gut microbiota is now recognized to exert an important influence on the absorption and pharmacokinetics of many compounds. Therefore, this study was designed to evaluate the effect of candidate probiotics belonging to the species Lactobacillus brevis, L. plantarum and L. bulgaricus on pharmacokinetics of enrofloxacin in healthy chickens. The probiotic administration leads to higher degree of metabolism of enrofloxacin to ciprofloxacin in liver. The antibacterial drug was significantly faster absorbed (k_ab of 0.61 ± 0.54 h^?1 and T_max 7.81 ± 3.52 h) at lower concentrations (C_max of 1.34 ± 0.18 μg·g^?1) during the first 24 h of treatment in the probiotic's group. The values of k_ab, T_max, and C_max for the group, treated solely with enrofloxacin, were 0.10 ± 0.065 h^?1, 15.42 ± 3.07 h, and 1.61 ± 0.24 μg·g^?1, respectively. A significantly higher concentration of enrofloxacin and its metabolite ciprofloxacin in the liver was observed in the group with the probiotic treatment. Disposition of both drugs was not significantly changed in the duodenum and in the jejunum. The selected dose is appropriate for treatment of infections caused by pathogens with MIC < 0.06 μg·mL^?1 irrespective of antibiotic administration alone or in combination with probiotics.     

淫羊藿对贵妃鸡胃肠道发育的影响

研究不同剂量的淫羊藿对贵妃鸡胃肠道的影响,为生产应用提供试验依据。选用400只贵妃鸡随机均分4组,每组设2个重复,分别为饮用淫羊藿提取物大剂量组(2 g/l),中剂量组(1 g/l),小剂量组(0.5 g/l),对照组饮用自来水,14日龄开始给药,连续饮用6周。每周末各组随机抽样8只,公母各半,空腹称重,心脏采血处死,解剖取消化器官:十二指肠、空肠、回肠、盲肠、直肠、肌胃、腺胃测定其平均器官重、长度及器官指数。淫羊藿5～8周龄十二指肠相对肠重均较对照组低,6周龄十二指肠单位肠重均较对照组低;6周龄空肠相对肠重均较对照组低,8周龄空肠相对肠重及单位肠重均较对照组低;4周龄回肠单位肠重较对照组高,8周龄回肠相对肠重及单位肠重均较对照组低;7周龄盲肠相对肠重及单位肠重较对照组高;6周龄直肠相对肠重较对照组高,7、8周龄直肠相对肠重及单位肠重较对照组低。淫羊藿能够促进贵妃鸡胃肠道的早期发育,并能有效防止贵妃鸡生长中期的肠增厚,有利于营养物质的吸收。     

Bacterial flora of the gastrointestinal tract of opossums.

The bacterial flora of the stomach, small intestine, cecum and bile from 20 healthy opossums (Didelphis virginiana) captured from the wild was studied. Results showed that their gastrointestinal flora was similar to that found in other small mammals but, in addition, opossums are heavily colonized by Salmonella spp., which might adversely affect their adequacy as laboratory animals for some experimental protocols.